<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.w3.org/1999/xhtml">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <form action="/login" method="post">
        用户名：<input name="username"><br>
        密码:<input type="password" name="password"><br>
        <input type="submit" value="登录">
        <span th:text="${session.err}" style="color:red;"></span>
    </form>
</body>
</html>